cpu/intel/model_67x: Add missing include

The added device.h file was indirectly picked from cpu.h, which will
have this include removed in a follow-up patch.

Change-Id: Ifc0a4800de3b1ef220ab1034934f583be8c527b0
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3826
Tested-by: build bot (Jenkins)
1 file changed